Chloroquine prophylaxis associated with high prevalence of Plasmodium falciparum pfcrt K76T mutation in people with sickle-cell disease in Benin City, Nigeria.

BACKGROUND & OBJECTIVES: High mortality and morbidity in sickle-cell disease has been associated with malaria infection especially in countries where chloroquine is used. Chloroquine resistance has been associated with the emergence of Pfcrt mutant genes. This study aimed at comparing the prevalence rate of Pfcrt T76 mutation in Plasmodium falciparum isolates from infected individuals with sickle-cell disease and sickle-cell trait. This study was carried out in Benin City between the months of April and June 2006. This period is marked with high transmission rate of malaria. METHODS: The genotype of the subjects was screened using haemoglobin electrophoresis system and the P. falciparum. Pfcrt genotyping was carried out using PCR-restriction fragment length polymorphism (RFLP). RESULTS: Four hundred and twenty-four subjects comprising of 207 haemoglobin AA, 136 haemoglobin AS and 81 haemoglobin SS typed individuals were enrolled for this study. No significant difference existed in the prevalence rate of malaria in the three groups (p > 0.05). However, the prevalence rate of Pfcrt K76T mutant gene was higher in the haemoglobin SS genotyped individuals than the haemoglobin AA and AS subjects (p < 0.05). INTERPRETATION & CONCLUSION: An uncontrolled use of chloroquine has been incriminated as the major cause of chloroquine resistance in Nigeria. Therefore, rapid intervention measures are needed as a matter of urgency to curb the up rise in the prevalence of the chloroquine resistant genes in our environment.

CD4 count, viral load and parasite density of HIV positive individuals undergoing malaria treatment with dihydroartemisinin in Benin City, Edo state, Nigeria.

BACKGROUND & OBJECTIVES: A prospective study on 72 HIV infected and 33 HIV negative individuals undergoing malaria treatment with dihydroartemisinin (Cotecxin) was undertaken to compare CD4 cells count, viral load and parasite density at two time-points, a baseline visit and a 9-day post-treatment visit. METHODS: CD4 count and viral load of the subjects were estimated using Dynabeads T4-T8 Quantification Protocol (Dyneal Biotech, Norway) and Amplicor HIV-1 Monitor Test respectively (Roche, United Kingdom). RESULTS: There was a significant decrease in CD4 count at 9-day post-treatment when compared with baseline value (p < 0.05) in HIV infected individuals with CD4 < or =200 cells/microl. Also, the 9-day post-treatment viral load value was statistically higher than the baseline value (p < 0.05). In HIV positive patients with CD4 >200 cells/microl, a marked significant increase was obtained when the mean viral load at baseline was compared to the 9-day post-treatment visit value (p <0.05). The mean parasite density in HIV positive subjects was statistically higher when compared to that of HIV negative individuals at baseline and 9-day post-treatment (p < 0.05). INTERPRETATION & CONCLUSION: The study as such may not confirm the impact of malaria infection on progression to AIDS, incorporating effective malaria control in HIV management programmes may improve tremendously the quality of life of HIV infected individuals.

Mechanical transmission of pathogenic organisms: the role of cockroaches.

BACKGROUND & OBJECTIVES: Cockroaches (Diploptera punctata) are basically tropical insects and will do their best to find a home that is both warm and moist. Their involvement in the transmission of tropical diseases is poorly investigated in Africa. METHODS: A study on the bacterial, fungal and parasitic profile of cockroaches trapped in and around houses in Ekpoma was carried out using standard microbiological techniques. RESULTS: Of a total of 234 cockroaches trapped from different sites (toilets, parlours, kitchens and bedrooms) in houses with pit latrines and water system, the bacterial, fungal and parasitic isolates were identical irrespective of the site, these included: E. coli, Klebsiella pneumoniae, Proteus vulgaris, Proteus mirabilis, Citrobacter freundii, Enterobacter cloacae, Salmonella sp, Pseudomonas aeruginosa, Serretia marcescens, S. aureus, S. feacalis, S. epidermidis, Aeromonas sp, Candida sp, Rhizopus sp, Aspergillus sp, Mucor sp, cysts of E. hystolitica, oocysts of C. parvum, C. cayetenensis and Isospora belli, cysts of Balantidium coli, ova of Ascaris lumbricoides, Anchylostoma deodunalae, Enterobius vermicularis, ova Trichuris trichura, larva of Strongyloides stercoralis. Cockroaches trapped in the toilets of houses with pit latrines had a mean bacterial and parasites count of 12.3 x 10(10) org/ml and 98 parasites/ml respectively, while those trapped in the houses with water system had a mean bacterial and parasitic count of 89.5 x 10(7) org/ml and 31 parasites/ml respectively. A bacterial count of 78.9 x 10(7) org/ml was recorded from cockroaches trapped from the kitchens of houses with pit latrines. On the other hand a mean bacterial and parasitic count of 23.7 x 10(6) org/ml and 19 parasites/ml were recorded from kitchens of houses with water system. INTERPRETATION & CONCLUSION: Cockroaches represent an important reservoir for infectious pathogens, therefore, control of cockroaches will substantially minimise the spread of infectious diseases in our environment.

A comparative study on the susceptibility of male and female albino mice to Trypanosoma brucei brucei.

BACKGROUND & OBJECTIVES: Trypanosomiasis has remained a major set-back in the development of livestock farming in tropical Africa. Thus the need for ascertaining the trypanotolerant levels of domestic animal breeds and possible improvement on them cannot be over-emphasised. METHODS: Level of trypanotolerance in animals was compared between sexes using albino mice infected with a Nigerian strain of Trypanosoma brucei brucei at a 50% mouse lethal dose (MLD50). RESULTS: The male mice showed unrestrained parasite growth with a prepatent period (PP) of two days and a mean survival period (MSP) of six days corresponding to a gradual decrease in packed cell volume (PCV), body weight, diet response and white blood cells (WBC) count to the time of death. Their female counterparts showed a PP of three days and MSP often days with a similar PCV gradient but a refractory WBC count. There was no significant difference in the differential leucocytes count in both sexes. However, the eosinophils count was significantly higher in the infected animals. It was found that female albino mice exercised more parasite restraint than their male counterparts. INTERPRETATION & CONCLUSION: The result suggests that the female animals may be more trypanotolerant hence may be more useful in protein production in trypanosomiasis endemic areas. However, further research using large domestic breeds like goats and sheep may be required to confirm the hypothesis.